I am having problems proceeding from a place in "IndianaJones and the infernal machine", at level Nub`s Tomb.

This is where I have problems:

"Follow the path to the right and you'll spot some water inside a tunnel on
the left. Leap into the water. Look out for the dangerous fish inside. Swim
down to the bottom and find the underwater tunnel. Pull the switch at the
back of the tunnel to raise the statue in the center of the room. Exit the
tunnel and hang a right to locate a ledge where you can pull yourself out of
the water."

My problems accurs when I am supposed to : push pull(ctrl).
Nothing happends,there is no reaction.
What might the problem be?
What should I do?